Laser beam processors for processing a workpiece with a laser beam such as laser markers for forming characters or the like on the workpiece, laser cutting machines for cutting the workpiece into a predetermined form, and laser welding machines for welding the workpiece are known. Various laser beam processors also have been developed; for example, laser soldering machines for soldering and glass sealing machines for binding or sealing a glass using a laser beam in solar cells or the like.
In these laser beam processors, two major methods described below are used to move a laser beam relative to the work surface of a workpiece.
For example, in the laser beam processor disclosed in Patent Reference 1, a laser beam is deflected in two directions using the two galvanometer mirrors and conducted to the work surface of a workpiece through an Fθ lens (this method is called “the deflecting method”). In Patent Reference 1, the laser beam can be focused on the work surface precisely by calculating the distance to the work surface by detecting the laser beam reflected on the work surface and by controlling the focus adjusting means disposed at the upstream of the galvanometer mirrors.
Also, in the laser beam processor disclosed in Patent Reference 2, the workpiece is disposed on the 3-degree-of-freedom stage that can move three-dimensionally and the laser beam is conducted to any position on the work surface by moving the stage relative to the laser beam (this method is called “the moving method”). In Patent Reference 2, the work surface can be precisely processed by moving the stage three-dimensionally and irradiating the work surface with the laser beam constantly vertically.